It would be difficult for evening all extensive monograph
to do justice to a proper classification and assessment of the nutritive
values of vegetarian diets as consumed in different parts of the World.
In the present paper, an attempt will be made to deal with only certain
aspects of the subject with particular reference to vegetarian diets
as consumed in India.

There have been several definitions of what constitutes
a vegetarian diet. There are some who would like to confine the definition
to only such articles of food as are exclusively of plant origin. There
are many who would like to include milk and eggs in the group. There
are some others who would extend the group to include fish. If we approach
the subject from purely ethical considerations, a vegetarian diet should
exclude only those forms of food which are obtained through causing
visible injury and even death to other forms of life. Even here, the
definition of injury and death should be confined to those higher forms
of life which have vital organs and circulatory systems similar to man
and whose suffering can be visibly seen. Strictly speaking, no life
in the world is possible without making use of materials elaborated
by other forms of life. When we pluck the leaves or fruits or even seeds
from a plant, we are causing a certain amount of injury. The plant does
suffer, but the effects are not visible to the eye. Similarly when we
take curds and buttermilk, we consume millions of bacteria and other
forms of-life, but there again, we do not notice anything with the naked
eye. On the other hand, when we slaughter a cow, a pig, a sheep. or
a, chicken, we can visibly see the nature of the cruelty inflicted on
the animal however merciful the method of killing may be. Human feelings
are prompted by reactions which they would themselves experience if
placed under similar conditions. We do not like to see a fellow-being
injured, let alone slaughtered. With this as the background we will
consider the nature and nutritive values of foods which are either of
plant origin or derived from animals without causing any visible suffering
or loss of life. This classification will naturally include milk and
eggs, but exclude fish.

Almost everywhere in the world there are two classes of
vegetarians: (1) those who consume such foods on the basis of religious
and sentimental considerations, and (2) those who eat a predominantly
vegetarian diet as the result of environmental conditions or necessity
- the latter chiefly on account of economic considerations. Thus, over
many parts of India, we find people who are classed as non-vegetarians,
but who can not afford to get even small amounts of milk, let alone
meat, fish, or eggs. From considerations of nutrition, we have taken
into account all people who eat a predominantly vegetarian diet, whether
by conviction or by necessity.

Over a large part of the World, the dietary patterns of
people are determined by food materials which are abundantly available
in the respective regions. This is particularly so in the case of vegetarian
diets, Thus, we find large sections of vegetarians whose diets are predominantly
based on rice, wheat, millets or root crops as the case may be. There
are other parts of the World where banana or bread-fruit forms the major
article of food. All such bulky articles of food are mainly sources
of starch and are important energy producers. In the majority of vegetarian
diets, starch forms the major part of the food. In many of the European
countries as also in America, starch (generally in the form of bread)
form hardly 10 to 15% of the diet. An extreme type of this would be
the diet of the Esquimos, which is made up predominantly of animal fat
and proteins and contains practically no starch, The slightly varied
types of diet would show that the human system is adaptable and can
gradually, if not immediately, adjust itself to any type of diet.

Starch, whether in the free condition or as associated
with other food ingredients, is mostly converted into sugar and burnt
in the human body. Part of it is also converted into fat. Starch by
itself cannot, however build up bones and tissues which are largely
made up of minerals and proteins respectively; the latter have to come
from some other sources.

The major part of the protein in vegetarian diets comes
from cereals. A fair part also comes from pulses, nuts, and also from
milk and eggs. The proteins from different sources supplement each other
and the quality is generally made up. According to International standards
one should consume as much as 70 gms. of protein per day, but there
is growing evidence to show, especially in the Tropics, that people
can maintain normal health even on smaller amounts of proteins. There
is however, a substantial amount of evidence to show that general well-being
and resistance to disease are associated with a generous intake and
utilization of proteins. Proteins should also be well balanced in respect
of essential amino-acids. If in addition to the cereal, the daily diet
also includes 5 to 10% of a good pulse, at least 10 ozs. of milk and
about two eggs it will then generally provide a fair blend of the essential
aminoacids. There are, of course, certain related factors and they have
some bearing on the protein value of the diet.

The proteins present in cereals and millets, as also pulses,
are associated with varying amounts of other components. Rice by itself
does not contain much fibre especially when it is polished. On the other
hand, millets and pulses include fair amounts of other substances which
are not easily assimilated. They also interfere, to varying extents,
with the utilization of the associated proteins and minerals. The extent
of such interference varies with the individual and is also determined
by other factors like age, occupation, etc. Speaking generally, many
vegetarian diets lead to bulky residues which are mostly voided. Certain
components-chiefly derived from vegetables, are liable to fermentation,
but that can be controlled if not completely eliminated.

A fair part of the diet of vegetarians - at any rate in
South India - is made up of vegetable dishes which are consumed in the
forms of curries, soups, and other preparations. There are dozens, if
not hundreds, of such vegetables and they have come into usage largely
as the result of long experience. Some of the vegetables especially
when they are soft and tender, are easily assimilated. Besides being
tasty they also provide minerals, vitamins, and a certain amount of
necessary roughage. On the other hand, there are also coarse and mature
vegetables which are often cheap and therefore consumed in large quantities.
A scientific classification of these has just been started. The evidence
already collected would show that there is a considerable amount of
truth in the earlier classification in relation to properties - some
of them being easy to digest and hence wholesome, some which are coarse
and slow to digest, and some which are only partly digested and yield
fermentable residues. Vegetables do affect the numbers and activities
of intestinal flora. Those which are slow to digest lead to abnormal
increase in the anaerobic and gas-forming bacteria in the cecum.

An important factor affecting the quality and the rate
of utilization of a vegetarian diet is the nature and quantity of fat
present in it. Generally speaking, fat in one form or another, improves
the taste of the food and hence is liked by all classes of consumers.
Fat is also a highly concentrated form of energy-giving food. At the
same time, fat beyond a level of 5 or 10% - whether in the form of ghee,
vanaspati, or oil - tends to retard growth unless the food is also adequately
supplemented with good proteins. As many of the poor vegetarian diets
are somewhat deficient in protein, there is a prima facie case
for reducing the amount of fat in the usual vegetarian diet. A large
section of consumers has found this by experience, though quite a large
number are still unaware of it. There is, of course, a certain amount
of individual variation in response to fat. The condition of health
is also an important factor. Speaking generally, boiled foods are generally
better digested and utilized than fried foods. In the latter case, the
fat itself undergoes a change on prolonged heating and forms harmful
ingredients that affect health. Fried food components are not also easily
digested by the body juices.

Vegetarian diets, especially in the tropics, are associated
with the use of certain food adjuncts and spices. It will be quite correct
to say that such diets would be monotonous and unappetizing without
the addition of these adjuncts. Tamarind and chilli form important food
adjuncts over a large part of South India. A liberal use of pickles
will also come in the same category. These definitely help to increase
the food intake in human subjects. It would be correct to say that the
food intake will go down by 50% or more if these food adjuncts are not
included in the diet. They do not, however, contribute directly to nutrition.
They do, however, indirectly contribute to growth, because of the effects
of larger intake. Their mode of action has not yet been clearly understood.
According to the Indian system of medicines, these food adjuncts are
considered to be harmful in the long run. Although some scientific work
has already been done on the subject, more information is needed before
definite conclusions can be drawn.

Spices and aromatics form important adjuncts to all types
of dietary and particularly to vegetarian diets. Most of them are included
in small quantities, and at these levels they are essentially flavouring
substances. They do not play any direct part in nutrition but they serve
indirectly as appetizers by facilitating a greater intake of food. At
high concentrations, some of the aromatics check the growth of putrefactive
and pathogenic organisms. This effect is seen in the preservation of
certain categories of pickles and sweets. The same effect is also seen
in the intestinal tract when they are taken in medicinal doses. Among
these, special mention may be made of garlic and asafoetida, both of
which act in the same way as some of the orally administerable antibiotics.
Most of the putrefactive and fermentative changes occurring in the digestive
tract are controlled by a liberal use of garlic, the potency being generally
proportional to the pungency of the product. A paste of raw garlic may
have an objectionable smell to a large section of people but the beneficial
effects are quite striking. Other aromatics have also similar effects,
but some of them may prove to be irritating and should be used with
care. All aromatics should be used in moderation, because it is generally
known that several of the organisms develop resistance to them - as
also to antibiotics-on continued usage.

Salt has a very important place in the dietary of vegetarians.
Most of the vegetarian diets, as consumed, especially in South India,
are somewhat acidic. They are not relished by the consumers unless an
adequate amount of salt is added to the diet. The average consumption
of salt in South India is of the order of 20 to 26 gms per day, though
many users are known to consume as much as 35 gms or even 60 gms per
day. The effect of the continued heavy intake of salt would require
thorough study. The partially purified sea salt, as consumed over a
large part of India, is associated with certain mineral impurities and
particularly calcium which are useful. One of the major defects of the
average vegetarian diets, especially when they do not include enough
milk, is inadequacy of calcium. The usual bazaar salt consumed with
our diet contributes 16 to 20% of the daily requirement of calcium.
Similarly Pan which is consumed by a large section of our people
also contributes some calcium because of the lime taken with it.

Vegetarian diets, if sufficiently varied, are not deficient
in most of the vitamins. In the poorer diets, many of the vitamins and
particularly A, B-1, D and B-12 are known to be deficient. If these
deficiencies are not properly corrected in early stages, much larger
quantities are required as therapeutic doses at a later stage.

Generally speaking, good vegetarian diets, if properly
planned, should provide all the requirements of human nutrition. At
the same time, it should be recognized that quite a large section of
people cannot afford a rich and varied vegetarian diet. They have to
subsist mainly on grains or roots and their diets show multiple deficiencies.
Considering their needs, there is a very strong case for supplementing
their diets with cheap and concentrated supplements that will provide
adequate amounts of proteins, minerals, and vitamins. Some of the best
sources of proteins are the oil-seed meals which are now used either
as animal feeds or as manures. The commercial products are unsuitable
for human consumption because of the dirt and fibre associated with
them. By careful selection and handling of the kernels, very clean attractive
meals can be obtained. By further processing. the meals can be made
into high class food supplements. The Multi-purpose Food is one such
product and even one or two ounces of it will correct the deficiency
in the diets of most sections of people. Such supplements are particularly
needed by growing children as also by expectant and nursing mothers.

Some special consideration should be given to vegetarian
diets which are predominantly based on root crops. Under the present
conditions prevalent in some of the densely peopled countries of the
world, the use of root crops has become a steadily growing necessity.
Root crops like tapioca or sweet potato, are very heavy yielders, capable
of giving several tons of starchy food per acre. It would be at least
3 to 4 times as much as one can expect in the form of foodgrains. These
starchy foods have, however, one major defect. They are highly deficient
in proteins. Tapioca, for instance, contains hardly 0.5% protein. If
one is to get 70 gms. of protein per day, one must eat about 35lb. of
the root which is physically impossible. It will naturally follow that
such diets consumed in the normal may will lead to protein deficiency
and various attendant disorders. Evidence has been adduced to show that
tapioca can replace about 25% of the rice or other cereal or millet
in the vegetarian diet for a short period, but it would not be desirable
to continue on such a diet indefinitely. If there is no adequate control,
there is always the risk of the consumers - especially of the low income
groups - over-eating such products. In the case of such crops, it is
absolutely necessary in the long range interests of the consumers, to
fortify them with adequate amounts of proteins before distribution to
people. One of the elegant methods of such fortification would be to
incorporate the protein-rich oil-seed meals along with tapioca or sweet
potato flour. A still more elegant and efficient method will be to to
make composite foods using such blends which can be consumed in the
same may as foodgrains. This type of work is now being done, for the
first time at the Central Food Techological Research Institute, Mysore,
and the products are being tried out on a large scale in the State of
Kernla. The advantage of such an approach would be that we can produce
much more food of good quality per acre, than would be possible in the
form of food-grains. There is already a fair amount of evidence to show
that food-grain production cannot be stepped up indefinilely in keeping
with the needs of the rapidly growing population. By taking advantage
of abundantly yielding crops and by application of scientific processing,
the problem of food shortage came be adequately dealt with on a long
range basis.

A major problem of the predominantly vegetarian countries
of tlie world, especially in East and South-East Asia, is the rapid
increase in population with the attendant consequences of various types.
Enforced vegetarianism is itself the result of the growing pressure
of population on land. It has often been argued that the vegetarian
diet and particularly the rice diet is responsible for the greater birth-rate,
among such people. It has also been reported that rice contains a principle
which leads to increased fertility of the human race. This is not, however,
substantiated by any scientific evidence. There is, in fact, nothing
to show that a vegetarian, and particularly the rice-eater, is necessarily
more prolific than a non-vegetarian. The non-vegetarian can be equally
if not more prolific, and experience of European countries especially
during and after the Wars, will show that their population can also
increase at a very rapid rate, The present check in population in those
countries are due to other factors among which scientific family-planning
plays a very big part. Even in India, the large increase in population
in recent years has been in States where rice is not the chief article
of diet. In any case, a vegetarian diet, particularly a rice diet, cannot
be incriminated as being exclusively responsible for the abnormal increase
in the population in the South.East Asian countries. The problem is
of course there and has to be tackled by the same effective methods
as have worked successfully in many of the Western countries.